Wu Yf

Panel reactive antibody in thalassemic serum inhibits proliferation and differentiation of cord blood CD34+ cells in vitro.

Thalassemic children are at a high risk of graft rejection in cord blood transplantation. To investigate this possible mechanism, the authors evaluated the effect of panel reactive antibody on the growth of CD34+ cells in vitro. On semisolid medium, CD34+ cells derived from cord blood were incubated with thalassemic serum, and colony-forming units were counted after 10 days of culture. After incubation with serum-specific panel reactive antibody, profound decreases were found in the numbers of CFU-GM, CFU-GEMM and BFU-E compared with controls. The results indicated that serum-specific panel reactive antibody might have an apparent inhibition effect on proliferation and differentiation of cord blood CD34+ cells.

Allogeneic peripheral blood stem cell transplantation in β-thalassemia

Six transfusion-dependent g -thalassemia major patients were treated with allogeneic peripheral blood stem cell (PBSC) transplant. The donors were HLA identical siblings except one donor who was a father with one-antigen mismatch of HLA-B loci. The donors were mobilized with G-CSF and PBSC was infused without manipulation. Engraftment was documented in all patients. Acute graft versus host disease (GvHD) was present in 4 patients but could be controlled with steroid or/and ATG. One patient died of hepatic veno-occlusive disease (HVOD) and survivors were all transfusion independent (ex-thalassemia). Chronic GvHD occurred in one patient. Allogeneic PBSC transplantation could achieve disease-free survival in g -thalassemia major patients.

Application of mesenchymal stromal cells in bone marrow transplantation for sensitized recipients.

Sensitized patients are at high risk for graft rejection during transplantation. It is of interest to investigate the effect of mesenchymal stromal cells (MSCs) in sensitized hematopoietic stem cell transplantation. MSCs were generated from bone marrow cells of BALB/c mice. The molecular markers of MSCs were detected by flow cytometry. MSCs labeled with green fluorescent dye were transplanted into nonsensitized and sensitized recipients, respectively. Homing of MSCs in vivo was monitored at different time points post-transplantation. Additionally, sensitized BALB/c mice under irradiation were transplanted with syngeneic MSCs and allogeneic bone marrow cells, and the rate of survival was monitored daily. The fourth passage of MSCs presented a typical spindle-shaped morphology and met the identification criteria of MSCs. Forty-eight hours post-transplantation, the homing of MSCs was found mainly in the bone morrow of nonsensitized recipients and the spleen of sensitized recipients, respectively. Moreover, all of the sensitized recipients died 12–16 days after receiving syngeneic MSCs and allogeneic bone marrow cells, with a median of 14 days. Our results suggest that the MSCs mainly homed to the spleen of sensitized recipients post-transplantation. MSCs could not enhance the engraftment of allogeneic bone marrow cells in sensitized recipients.